apr
I have the following code
Repo.transaction(fn -> Blog |> where(title: ^title) |> Repo.stream() |> Flow.from_enumerable() |> Flow.each(fn x -> IO.inspect x end) |> Flow.run() end)
When I run this, I get the error: (RuntimeError) cannot reduce stream outside of transaction
Is Ecto and Flow not supposed to be used in this manner?
Thanks!
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mbuhot
I believe the stream must be used in the same process that created the transaction.
There was some work towards GenStage integration in Ecto: Introduce Ecto.Adapters.SQL.Stage by fishcakez · Pull Request #2028 · elixir-ecto/ecto · GitHub but it’s been closed.
apr
Darn. Oh well. Guess I need to use Task.async_stream
josevalim
We will support this likely on Ecto 3.1. It won’t make the cut for Ecto 3.0 but it is planned to happen at some point.
samuelralak
Has it made the cut yet?
cblavier
Hey @josevalim, do you know if this is supported in Ecto now? Thanks
josevalim
It has not. Unless someone works on it (or sponsors someone do to the work), it is unlikely to be added.